This disclosure relates generally to airbag modules for vehicles. Specifically, this disclosure relates to variable tether systems for inflatable cushions and airbag modules.
Airbag modules have become common in modern automobiles. An airbag module typically comprises an inflatable cushion and an inflator within a housing. The module is installed in a desired position within the vehicle, such as the steering wheel, the dashboard, the seat, the A-pillar, and other locations. The inflatable cushion is stored in a folded position within the housing in fluid communication with the inflator. In response to an activation event or occurrence, a sensor provides a signal for activating the inflator. The inflator provides a supply of inflating gas to the cushion to inflate the cushion, deploying it from the housing into the vehicle.
Various methods have been employed to more closely tie the inflation level of the inflatable cushion to specific conditions. For example, dual stage inflators have been used to increase or decrease the level of inflation of the inflatable cushion. Alternatively, variable venting schemes have been used to direct a portion of a generated inflation gas away from the cushion. Further, variable tethering systems have been used to restrict or vary the overall cushion volume.
A variable tether system adapted for use in an inflatable cushion of an airbag module having a first pair of tether elements each having a first end and a second end, the first ends each being secured to inner portions of the inflatable cushion and the second ends each being secured to inner portions of the inflatable cushion, the first ends each being secured to the inflatable cushion at positions remote from the second ends and the second ends being secured to the inflatable cushion at a location closer to an inflation opening of the inflatable cushion than the first ends, wherein each of the first pair of tether elements has a portion between each of the first and second ends which is not secured to the inflatable cushion; and a second pair of tether elements each having a first side and a second side, the first side of one of said second pair of tether elements being secured to a portion of one of the first pair of tether elements and the first side of the other one of the second pair of tether elements being secured to the portion of the other one of the first pair of tether elements and the second sides are configured for being releasably secured to an actuation mechanism.
An airbag module having a variable tether system is also provided. The module comprises a housing, an inflatable cushion, an inflator, an actuation mechanism, and tether elements. The first tether element has a first end secured to a first inner portion of the inflatable cushion and a second end secured to a second inner portion of the inflatable cushion. The second tether element has a first side that mates with the first tether element at a point between the first and second ends. The actuation mechanism is configured to selectively retain or release the second side of the second tether element. The second tether element restrains the first tether element to a first length when the second tether element is retained so that the inflatable cushion expands to a first expanded state. The first length is less than a full length of the first tether element. The second tether element allows the first tether element to extend to the full length when the second tether element is released so that the inflatable cushion expands to a second expanded state.
An airbag module, comprising: a housing; an inflatable cushion for deployment from the housing; an inflator in fluid communication with the inflatable cushion and for providing a quantity of inflation gas to deploy the inflatable cushion from the housing; a variable tether system adapted for use in an inflatable cushion of an airbag module, comprising: a first pair of tether elements each having a first end and a second end, the first ends each being secured to inner portions of the inflatable cushion and the second ends each being secured to inner portions of the inflatable cushion, the first ends each being secured to the inflatable cushion at positions remote from the second ends and the second ends being secured to the inflatable cushion at a location closer to an inflation opening of the inflatable cushion, wherein each of the first pair of tether elements has a portion between each of the first and second ends which is not secured to the inflatable cushion; and a second pair of tether elements each having a first side and a second side, the first side of one of said second pair of tether elements being secured to a portion of one of said first pair of tether elements and the first side of the other one of the second pair of tether elements being secured to the portion of the other one of the first pair of tether elements, the second sides being configured for being releasably secured to an actuation mechanism.
The above-described and other features of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.